I had a safety issue with a front QR "back in the day" We went camping and I had to remove the front wheel to fit the bike in the vehicle. Later that night I popped a wheelie to impress a girl and the front wheel fell out. Feet in toe clips - the aftermath wasn't pretty - she wasn't impressed.
Operator error forgot to tighten the QR when I put the wheel back in. I'll freely admit copious amounts of alcohol were also involved.